Heat Stress and the Bull Sperm Transcriptome: Molecular Mechanisms, Fertility, and Epigenetic Inheritance

Abstract

Simple Summary Heat stress (HS) is characterized by an increase in core body temperature due to the failure of thermoregulatory mechanisms to cope with external conditions. In males, HS leads to an increase in testicular temperature, reducing spermatozoa production and quality as well as the ability of the spermatozoa to fertilize the female gamete and develop into healthy embryos. The molecular mechanisms behind HS-induced changes are not yet fully understood. This review aims to elucidate several aspects of bovine sperm physiology and the associated molecular mechanisms. Particular attention is given to the cascade of functional, cellular, and molecular events triggered by elevated temperatures in mature spermatozoa with the aim of disclosing strategies to mitigate the effects of HS and maintain bull fertility.